Glossary of Terms

PHYSICAL EYE CONDITIONSAcuityClearness of vision. Standard is 6/6 which means the individual sees at 6 meters what they should see at that distance. Metric equivalent of 20/20 vision.

AccommodationAbility to change and control the focusing of the eye.

AstigmatismCondition where vision is distorted because the front of the eye is not totally spherical ie. it is shaped more like a rugby ball than a soccer ball. Clear vision is restored by an appropriate lens.

BinocularUsing both eyes together.

ConvergenceAn inability of the eyes to turn towards each other, or sustain convergence.

FusionAbility to perceive objects seen with the two eyes as a single object.

HyperopiaLong-sightedness. It is easier to see in the distance than close up. A small amount of long-sightedness is normal in children but may affect their comfort and concentration at close distances ie. reading and writing.

MyopiaShort-sightedness. It is easier to see close up than in the distance.

MotilitiesMovement of the eyes following a moving target.

MultifocalA lens with an upper area for seeing in the distance and a lower area with a different prescription for close work.

PerceptionInterpreting the information received by the eyes.

Plus Lens (Convex) Changes the path of light so that it focuses closer. Given to correct long-sightedness.

Minus Lens(Concave) Changes the path of light so that focus is farther away. Given to correct short-sightedness.

Visual processing and perception skills/Visual UnderstandingPerception is the capacity to interpret or give meaning to what is seen. The following are specific perception skills. A "form" is a piece of visual information like a letter, number or shape.